For gear shifting operations in classically configured stepped motor vehicle transmission devices, the following three steps—starting from the old gear—are run through in timed sequence: “disengagement of the old gear”—“selection”—“engagement of the target gear”. Moreover, motor vehicle transmission designs have become known in which the selection or select movement may occur before the disengagement of the old gear. In such configurations, it is provided, for example, that a main control element or shift finger is essentially responsible only for the engagement of gears and additional geometries take on the function of disengaging gears. In this context, secondary control elements are used for the disengagement function. It is further known that the additional geometries are located on the one hand on central shift shafts and on the other hand on shift mouthpieces that are provided on final output mechanisms or shift forks or shift rails.
The disengagement geometries as a rule are operative in gates in which the shift finger is not active. In this context, it may be provided that a fixed assignment between shift finger and disengagement geometry thereby simultaneously represents an active gear lock. Structural implementations of this approach are therefore also referred to as “active interlock”.
In such an “active interlock”, it is generally provided that the main control element or the shift finger may be moved back into a central or neutral position without disengaging the gear. The select movement is therefore possible before the gear is disengaged.
A transmission device known to the applicant in which the selection may be carried out before the disengagement of the old gear, or which is provided with “active interlock”, is shown in partial view in FIGS. 4a to 4f. This transmission device 100 has several shift rails 104, each of which is a component of a particular final control mechanism 102. Each of the final control mechanisms 102 therefore has one shift rail 104.
In the illustration according to FIG. 4a, shown in particular is a shift rail 104 and the cross-section of a secondary control element 106. This secondary control element 106—just like main control element 108 shown in FIG. 4c—is rotatably mounted, and in particular about an axis 110. For this purpose main control element 108 and secondary control element 106—axially offset—are disposed on a rotating or actuating shaft 112 that is mounted in a rotatable and axially displaceable manner. A cutout, which represents a shift mouthpiece 114, is provided in each of shift rails 104. In FIG. 4a, both elements, that is, shift rail 104 and secondary control element 106, are located in the “neutral” shift position.
Shift mouthpiece 114 has one or two edges 116 and one or two flanks 118 that come into contact with secondary control element 106 via flanks 120 or edge 122 to disengage the gears. If flank 120 comes into contact with edge 116 as a result of a corresponding rotation of secondary control element 106 and triggers a translatory movement of shift rail 104 (see arrow 124), a “movement in the same direction” for secondary actuating element 106 and shift rail 104 is produced. If flank 122 comes into contact with edge 116 as a result of a corresponding rotation of secondary control element 106 and triggers a translatory movement of shift rail 104 (see arrow 124), a “movement in the opposite direction” for secondary control element 106 and shift rail 104 is produced. The connection is symbolically represented in FIG. 4b. 
FIG. 4c shows shift rail 104 on the plane of main control element 108. Main control element 108 comes into contact with edge 130 of shift rail 104 via flank 128 of this main control element 108 as a result of the corresponding rotation of this main control element 108 and moves shift rail 104 in a translatory manner (see arrow 124). The disengagement and engagement movement phases occur according to the known scheme of active interlock. Therefore, it is provided in particular that when there is a movement, in this case rotation, of main control element 108 out of its neutral position (see FIG. 4c), secondary control elements 106 in other planes cooperate with shift rails 104 of the same partial transmission in such a manner that—if present—a shift rail 104 that is positioned outside of its neutral position is moved into its neutral position and these shift rails 104 that are positioned in other planes are locked in their neutral position by these secondary control elements 106 via their shift mouthpieces 114. When there is a continued rotation of main control element 108, it then acts on shift rail 104—inside of which it is positioned—in such a manner that this shift rail 104 is positioned in a disengaged position such that a gear ratio step is engaged via this shift rail 104.
FIG. 4d shows the projection from the different planes of main 108 and secondary control element 106. Both elements 106, 108 rotate continuously synchronously and actuate shift rails 104 of a partial transmission when a parallel shift transmission (PST) is used.
FIG. 4e shows secondary control element 106 when a “movement in the opposite direction” of shift rail 104 at an advanced angle of rotation is produced. For the purposes of comparison, FIG. 4f shows secondary control element 106 when a “movement in the same direction” of shift rail 104 is produced. The position of flank 118 at the height of axis of rotation 110 of secondary control element 106 in the position according to FIG. 4e leads to the problem that secondary control element 106 comes into contact with shift rail 104 at a very poor force application angle. Consequently, the resulting force for the translatory movement of shift rail 104 is substantially reduced, which under unfavorable friction or tolerance situations may lead to jamming. On the other hand, short-term jamming exerts an additional bending stress on shift rail 104.
In the position according to FIG. 4f, secondary control element 106 comes into contact with shift rail 104 at a favorable or more favorable force application angle. A jamming or a bending stress at the force application angle that is operative there is insignificant.
From German Patent Application 102 06 561 A1, a transmission device is known to the applicant in which the selection may be carried out before the disengagement of the old gear or which is provided with “active interlock”. There it is proposed (FIG. 7, Illustration a, b, d, e), that the secondary control element be configured as a double cam (Illustration a, d) or as recesses or with recesses (Illustration d, e). In this neutral position, these secondary control elements are aligned in such a manner that they essentially extend in the displacement direction of the shift rail or the shift fork. Also in these designs, the force ratios when the shift fork is moved back into its neutral position are unfavorable. Furthermore, a design is proposed there (FIG. 7, Illustration c) in which the secondary control elements are configured in rectangular shapes and in their neutral position extend perpendicular to the direction of displacement of the shift fork. When the shift rail is moved into its neutral position, these rectangular-shaped areas of the secondary control element are engaged with likewise rectangular-shaped cutouts of the shift mouthpiece disposed—transverse to the displacement direction of the shift fork—above and below. It has been proven that the force ratios in this design are such that there is a rather high susceptibility to wear.